audk/SecurityPkg/RandomNumberGenerator/RngDxe/AArch64/RngDxe.c

127 lines
4.9 KiB
C

/** @file
RNG Driver to produce the UEFI Random Number Generator protocol.
The driver will use the RNDR instruction to produce random numbers.
RNG Algorithms defined in UEFI 2.4:
- EFI_RNG_ALGORITHM_SP800_90_CTR_256_GUID
- EFI_RNG_ALGORITHM_RAW - Unsupported
- EFI_RNG_ALGORITHM_SP800_90_HMAC_256_GUID
- EFI_RNG_ALGORITHM_SP800_90_HASH_256_GUID
- EFI_RNG_ALGORITHM_X9_31_3DES_GUID - Unsupported
- EFI_RNG_ALGORITHM_X9_31_AES_GUID - Unsupported
Copyright (c) 2021, NUVIA Inc. All rights reserved.<BR>
Copyright (c) 2013 - 2018, Intel Corporation. All rights reserved.<BR>
(C) Copyright 2015 Hewlett Packard Enterprise Development LP<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/TimerLib.h>
#include <Protocol/Rng.h>
#include "RngDxeInternals.h"
/**
Produces and returns an RNG value using either the default or specified RNG algorithm.
@param[in] This A pointer to the EFI_RNG_PROTOCOL instance.
@param[in] RNGAlgorithm A pointer to the EFI_RNG_ALGORITHM that identifies the RNG
algorithm to use. May be NULL in which case the function will
use its default RNG algorithm.
@param[in] RNGValueLength The length in bytes of the memory buffer pointed to by
RNGValue. The driver shall return exactly this numbers of bytes.
@param[out] RNGValue A caller-allocated memory buffer filled by the driver with the
resulting RNG value.
@retval EFI_SUCCESS The RNG value was returned successfully.
@retval EFI_UNSUPPORTED The algorithm specified by RNGAlgorithm is not supported by
this driver.
@retval EFI_DEVICE_ERROR An RNG value could not be retrieved due to a hardware or
firmware error.
@retval EFI_NOT_READY There is not enough random data available to satisfy the length
requested by RNGValueLength.
@retval EFI_INVALID_PARAMETER RNGValue is NULL or RNGValueLength is zero.
**/
EFI_STATUS
EFIAPI
RngGetRNG (
IN EFI_RNG_PROTOCOL *This,
IN EFI_RNG_ALGORITHM *RNGAlgorithm OPTIONAL,
IN UINTN RNGValueLength,
OUT UINT8 *RNGValue
)
{
EFI_STATUS Status;
if ((RNGValueLength == 0) || (RNGValue == NULL)) {
return EFI_INVALID_PARAMETER;
}
if (RNGAlgorithm == NULL) {
//
// Use the default RNG algorithm if RNGAlgorithm is NULL.
//
RNGAlgorithm = PcdGetPtr (PcdCpuRngSupportedAlgorithm);
}
if (CompareGuid (RNGAlgorithm, PcdGetPtr (PcdCpuRngSupportedAlgorithm))) {
Status = RngGetBytes (RNGValueLength, RNGValue);
return Status;
}
//
// Other algorithms are unsupported by this driver.
//
return EFI_UNSUPPORTED;
}
/**
Returns information about the random number generation implementation.
@param[in,out] RNGAlgorithmListSize On input, the size in bytes of RNGAlgorithmList.
On output with a return code of EFI_SUCCESS, the size
in bytes of the data returned in RNGAlgorithmList. On output
with a return code of EFI_BUFFER_TOO_SMALL,
the size of RNGAlgorithmList required to obtain the list.
@param[out] RNGAlgorithmList A caller-allocated memory buffer filled by the driver
with one EFI_RNG_ALGORITHM element for each supported
RNG algorithm. The list must not change across multiple
calls to the same driver. The first algorithm in the list
is the default algorithm for the driver.
@retval EFI_SUCCESS The RNG algorithm list was returned successfully.
@retval EFI_BUFFER_TOO_SMALL The buffer RNGAlgorithmList is too small to hold the result.
**/
UINTN
EFIAPI
ArchGetSupportedRngAlgorithms (
IN OUT UINTN *RNGAlgorithmListSize,
OUT EFI_RNG_ALGORITHM *RNGAlgorithmList
)
{
UINTN RequiredSize;
EFI_RNG_ALGORITHM *CpuRngSupportedAlgorithm;
RequiredSize = sizeof (EFI_RNG_ALGORITHM);
if (*RNGAlgorithmListSize < RequiredSize) {
*RNGAlgorithmListSize = RequiredSize;
return EFI_BUFFER_TOO_SMALL;
}
CpuRngSupportedAlgorithm = PcdGetPtr (PcdCpuRngSupportedAlgorithm);
CopyMem (&RNGAlgorithmList[0], CpuRngSupportedAlgorithm, sizeof (EFI_RNG_ALGORITHM));
*RNGAlgorithmListSize = RequiredSize;
return EFI_SUCCESS;
}